Sophia Statistics – Unit 3 Milestone Exam
Questions PRACTICE QUESTIONS PLUS
RATIONALES 2026 |INSTANT DOWNOAD PDF
1. What is probability best defined as?
A. The number of favorable outcomes
B. The ratio of favorable outcomes to total possible outcomes
C. The number of total outcomes
D. The difference between outcomes
Correct answer: B — Probability measures the likelihood of an
event occurring by dividing favorable outcomes by total possible
outcomes.
2. What is the range of any probability value?
A. −1 to 1
B. 0 to 10
C. 0 to 1
D. 1 to 100
Correct answer: C — All probabilities must fall between 0
(impossible) and 1 (certain).
3. If an event is impossible, its probability is:
A. 1
B. 0.5
C. 0
D. −1
Correct answer: C — An impossible event has a probability of 0.
,4. What is the probability of a certain event?
A. 0
B. 0.5
C. 1
D. Undefined
Correct answer: C — A certain event always has a probability of
1.
5. What does the complement of an event represent?
A. The same event
B. All outcomes not in the event
C. Only favorable outcomes
D. Independent outcomes
Correct answer: B — The complement includes every outcome
where the event does not occur.
6. If P(A) = 0.3, what is P(Aᶜ)?
A. 0.3
B. 0.7
C. 1.3
D. −0.3
Correct answer: B — The complement is found by 1 − P(A).
7. Which rule is used to find the probability of A or B?
A. Multiplication rule
B. Addition rule
C. Complement rule
D. Counting rule
, Correct answer: B — The addition rule is used for “or”
probabilities.
8. For mutually exclusive events, P(A or B) equals:
A. P(A) × P(B)
B. P(A) − P(B)
C. P(A) + P(B)
D. 1 − P(A)
Correct answer: C — Mutually exclusive events do not overlap,
so probabilities are added.
9. Events that cannot occur at the same time are called:
A. Independent
B. Complementary
C. Mutually exclusive
D. Conditional
Correct answer: C — Mutually exclusive events share no
outcomes.
10. Which formula applies to non-mutually exclusive events?
A. P(A) + P(B)
B. P(A) × P(B)
C. P(A) + P(B) − P(A and B)
D. 1 − P(A)
Correct answer: C — Overlapping probabilities must subtract
the intersection.
Questions PRACTICE QUESTIONS PLUS
RATIONALES 2026 |INSTANT DOWNOAD PDF
1. What is probability best defined as?
A. The number of favorable outcomes
B. The ratio of favorable outcomes to total possible outcomes
C. The number of total outcomes
D. The difference between outcomes
Correct answer: B — Probability measures the likelihood of an
event occurring by dividing favorable outcomes by total possible
outcomes.
2. What is the range of any probability value?
A. −1 to 1
B. 0 to 10
C. 0 to 1
D. 1 to 100
Correct answer: C — All probabilities must fall between 0
(impossible) and 1 (certain).
3. If an event is impossible, its probability is:
A. 1
B. 0.5
C. 0
D. −1
Correct answer: C — An impossible event has a probability of 0.
,4. What is the probability of a certain event?
A. 0
B. 0.5
C. 1
D. Undefined
Correct answer: C — A certain event always has a probability of
1.
5. What does the complement of an event represent?
A. The same event
B. All outcomes not in the event
C. Only favorable outcomes
D. Independent outcomes
Correct answer: B — The complement includes every outcome
where the event does not occur.
6. If P(A) = 0.3, what is P(Aᶜ)?
A. 0.3
B. 0.7
C. 1.3
D. −0.3
Correct answer: B — The complement is found by 1 − P(A).
7. Which rule is used to find the probability of A or B?
A. Multiplication rule
B. Addition rule
C. Complement rule
D. Counting rule
, Correct answer: B — The addition rule is used for “or”
probabilities.
8. For mutually exclusive events, P(A or B) equals:
A. P(A) × P(B)
B. P(A) − P(B)
C. P(A) + P(B)
D. 1 − P(A)
Correct answer: C — Mutually exclusive events do not overlap,
so probabilities are added.
9. Events that cannot occur at the same time are called:
A. Independent
B. Complementary
C. Mutually exclusive
D. Conditional
Correct answer: C — Mutually exclusive events share no
outcomes.
10. Which formula applies to non-mutually exclusive events?
A. P(A) + P(B)
B. P(A) × P(B)
C. P(A) + P(B) − P(A and B)
D. 1 − P(A)
Correct answer: C — Overlapping probabilities must subtract
the intersection.
